Elevator linear propulsion system with cooling device

ABSTRACT

An elevator system includes an elevator car constructed and arranged to travel in a hoistway. A linear propulsion system of the elevator system is configured to impart a force upon the elevator car to control movement of the car. The linear propulsion system includes a secondary portion mounted to the elevator car and having a plurality of magnets. A first primary portion of the linear propulsion system includes a mounting assembly, a plurality of coils engaged to the mounting assembly, and a first cooling device including at least one conduit projecting outward from the mounting assembly and into the hoistway for transferring heat.

CROSS-REFERENCES TO RELATED APPLICATIONS

This patent application is a U.S. National Stage Application ofPCT/US2016/045748, filed Aug. 5, 2016, which claims the priority of U.S.Provisional Application No. 62/202,515, filed Aug. 7, 2015, each ofwhich are incorporated herein by reference in their entirety.

BACKGROUND

The subject matter disclosed herein relates generally to the field ofelevators, and more particularly to a multicar, self-propelled elevatorsystem having a cooled linear propulsion system.

Self-propelled elevator systems, also referred to as ropeless elevatorsystems, are useful in certain applications (e.g., high rise buildings)where the mass of the ropes for a roped system is prohibitive and thereis a desire for multiple elevator cars to travel in a single lane. Thereexist self-propelled elevator systems in which a first lane isdesignated for upward traveling elevator cars and a second lane isdesignated for downward traveling elevator cars. At least one transferstation is provided in the hoistway to move cars horizontally betweenthe first lane and second lane.

Existing self-propelled elevators employ linear motors having primaryportions that include stator coils engaged to a support structure. Dutycycle loads between coils and/or coil modules may vary from two percentto an excess of thirty percent depending upon the car speed and locationwithin the hoistway. Because the duty cycle varies, the coils dissipatespatially varying heat loads in the hoistway causing a variance in coilefficiency and useful life from one coil to the next. Improvements incoil cooling is desirable.

SUMMARY

An elevator system according to one, non-limiting, embodiment of thepresent disclosure includes an elevator car constructed and arranged totravel in a hoistway; and a linear propulsion system configured toimpart force to the elevator car, the linear propulsion systemincluding; a first primary portion including a mounting assembly, aplurality of coils engaged to the mounting assembly, and a first coolingdevice including at least one conduit loop at least partially embeddedin the mounting assembly for flowing cooling fluid.

Additionally to the foregoing embodiment, the linear propulsion systemincludes a secondary portion mounted to the elevator car and including aplurality of magnets.

In the alternative or additionally thereto, in the foregoing embodiment,the at least one conduit loop is partially embedded in a panel of themounting assembly supporting the plurality of coils.

In the alternative or additionally thereto, in the foregoing embodiment,the at least one conduit loop is partially in a cavity defined at leastin part by a panel of the mounting assembly that supports the coilsdisposed in the cavity.

In the alternative or additionally thereto, in the foregoing embodiment,the at least one conduit loop is made of a material having a coefficientof thermal conductivity that is about greater than 100 watts per meterkelvin.

In the alternative or additionally thereto, in the foregoing embodiment,the elevator system includes a rail disposed in and extending along thehoistway, and wherein the mounting assembly is engaged to the rail andthe first cooling device includes a plurality of cooling fins projectingoutward from the rail into the hoistway with the at least one conduitloop extending through each one of the plurality of cooling fins.

In the alternative or additionally thereto, in the foregoing embodiment,each one of the plurality of cooling fins substantially extendvertically.

In the alternative or additionally thereto, in the foregoing embodiment,the first cooling device includes a pump interposed in the at least oneconduit loop for driving the cooling fluid flow.

In the alternative or additionally thereto, in the foregoing embodiment,the cooling device includes a plurality of cooling fins located outsideof the hoistway with the at least one conduit loop extending througheach one of the plurality of cooling fins.

In the alternative or additionally thereto, in the foregoing embodimentthe elevator system includes a rail disposed in and extending along thehoistway, and wherein the mounting assembly includes an electricallynon-conductive panel engaged to the plurality of coils and a bracketengaged between the non-conductive panel and the rail with the at leastone conduit loop partially embedded in the bracket.

In the alternative or additionally thereto, in the foregoing embodiment,the cooling device includes a heat exchanger interposed with the atleast one conduit loop.

In the alternative or additionally thereto, in the foregoing embodiment,the heat exchanger is located outside of the hoistway.

In the alternative or additionally thereto, in the foregoing embodiment,the heat exchanger is a liquid-to-liquid heat exchanger.

In the alternative or additionally thereto, in the foregoing embodiment,the heat exchanger is a liquid-to-air heat exchanger and the coolingdevice includes a fan for moving air through the heat exchanger.

In the alternative or additionally thereto, in the foregoing embodimentthe elevator system includes a second primary portion including a secondcooling device including a plurality of heat pipes.

In the alternative or additionally thereto, in the foregoing embodimentthe elevator system includes a second primary portion including a secondcooling device including a plurality of solid conduits constructed andarranged to transfer heat conductively.

An elevator linear propulsion system according to another, non-limiting,embodiment includes a substantially vertical rail; a first primaryportion including a plurality of first electrical coils, a firstmounting assembly, and a first cooling device including a plurality ofsolid conduits constructed and arranged to conduct heat out of the firstmounting assembly; and a second primary portion including a plurality ofsecond electrical coils, a second mounting assembly, and a secondcooling device including at least one conduit loop for flowing coolingfluid, and wherein the at least one conduit loop extends partiallythrough the mounting assembly for cooling the mounting assembly.

Additionally to the foregoing embodiment, the first and second primaryportions are modular portions distributed along the rail.

In the alternative or additionally thereto, in the foregoing embodiment,the first primary portion includes a duty cycle of about less thanthirty percent and the second primary portion includes a duty cycle ofabout greater than thirty percent.

In the alternative or additionally thereto, in the foregoing embodiment,the distribution of the first and second cooling devices is a functionof elevator car duty cycle.

A method of operating an elevator system according to another,non-limiting, embodiment includes operating an elevator car via a firstprimary portion having a duty cycle of greater than thirty percent; andflowing cooling fluid through a conduit loop of a first cooling devicefor cooling electrical coils of the first primary portion.

Additionally to the foregoing embodiment, the method includes operatingan elevator car via a second primary portion having a duty cycle of lessthan thirty percent; and reducing temperature of a support assemblyconstructed and arrange to support electrical coils of the secondprimary portion via heat conduction through a plurality of conduits of asecond cooling device.

The foregoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated otherwise.These features and elements as well as the operation thereof will becomemore apparent in light of the following description and the accompanyingdrawings. However, it should be understood that the followingdescription and drawings are intended to be exemplary in nature andnon-limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features will become apparent to those skilled in the art fromthe following detailed description of the disclosed non-limitingembodiments. The drawings that accompany the detailed description can bebriefly described as follows:

FIG. 1 depicts a multicar elevator system in an exemplary embodiment;

FIG. 2 is a top down view of a car and portions of a linear propulsionsystem in an exemplary embodiment;

FIG. 3 is a front view of portions of a linear propulsion system in anexemplary embodiment;

FIG. 4 is a schematic of the linear propulsion system;

FIG. 5 is a partial exploded view of a primary portion of the linearpropulsion system;

FIG. 6 is a partial perspective view of the primary portion;

FIG. 7 is a partial perspective view of the linear propulsion systemillustrating a cooling device of the primary portion;

FIG. 8 is a perspective view of a panel of the primary portionillustrating conduits of the cooling device of FIG. 7;

FIG. 9 is a partial perspective view of a second embodiment of theprimary portion;

FIG. 10 is a perspective view of a panel of the primary portionillustrating conduits of the cooling device of FIG. 9;

FIG. 11 is a schematic of a third embodiment of a cooling device; and

FIG. 12 is a schematic of a fourth embodiment of a cooling device.

DETAILED DESCRIPTION

FIG. 1 depicts a self-propelled or ropeless elevator system 20 in anexemplary embodiment that may be used in a structure or building 22having multiple levels or floors 24. Elevator system 20 includes ahoistway 26 having boundaries defined by the structure 22 and at leastone car 28 adapted to travel in the hoistway 26. The hoistway 26 mayinclude, for example, three lanes 30, 32, 34 with any number of cars 28traveling in any one lane and in any number of travel directions (e.g.,up and down). For example and as illustrated, the cars 28 in lanes 30,34, may travel in an up direction and the cars 28 in lane 32 may travelin a down direction.

Above the top floor 24 may be an upper transfer station 36 thatfacilitates horizontal motion to elevator cars 28 for moving the carsbetween lanes 30, 32, 34. Below the first floor 24 may be a lowertransfer station 38 that facilitates horizontal motion to elevator cars28 for moving the cars between lanes 30, 32, 34. It is understood thatthe upper and lower transfer stations 36, 38 may be respectively locatedat the top and first floors 24 rather than above and below the top andfirst floors, or may be located at any intermediate floor. Yet further,the elevator system 20 may include one or more intermediate transferstations (not illustrated) located vertically between and similar to theupper and lower transfer stations 36, 38.

Referring to FIGS. 1 through 3, cars 28 are propelled using a linearpropulsion system 40 having a fixed, primary portion 42 (e.g., twoillustrated in FIG. 2), a moving secondary portion 44 (e.g., twoillustrated in FIG. 2), and a control system 46 (see FIG. 4). Theprimary portion 42 includes a plurality of windings or coils 48 mountedat one or both sides of the lanes 30, 32, 34 in the hoistway 26. Thesecondary portion 44 may include two rows of permanent magnets 50A, 50Bmounted to one or both sides of cars 28. Primary portion 42 is suppliedwith drive signals from the control system 46 to generate a magneticflux that imparts a force on the secondary portion 44 to controlmovement of the cars 28 in their respective lanes 30, 32, 34 (e.g.,moving up, down, or holding still). It is further contemplated andunderstood that the linear propulsion system 40 may be a synchronousreluctance linear motor with the secondary portion 44 being formed by asteel, ferromagnetic plate with saliency. Moreover, the linearpropulsion system 40 may be an induction linear motor and may include asecondary portion 44 being formed by a steel, ferromagnetic, plate witha conductive sheet with a material made, for example, of aluminum,copper, and others.

Referring to FIGS. 2 and 3, a first secondary portion 44 of the linearpropulsion system 40 is mounted on a first side of the car 28 and asecond secondary portion 44 is mounted on an opposite side of the car28. The primary portion 42 (which may be two, back-to-back, primaryportions 42) is generally positioned between the magnets 50A, 50B of thesecondary portion 44. It is contemplated and understood that any numberof secondary portions 44 may be mounted to the car 28, and any number ofprimary portions 42 may be associated with the secondary portions 44 inany number of configurations.

Referring to FIG. 4, the control system 46 may include power sources 52,drives 54, buses 56 and a controller 58. The power sources 52 areelectrically coupled to the drives 54 via the buses 56. In onenon-limiting example, the power sources 52 may be direct current (DC)power sources. DC power sources 52 may be implemented using storagedevices (e.g., batteries, capacitors), and may be active devices thatcondition power from another source (e.g., rectifiers). The drives 54may receive DC power from the buses 56 and may provide drive signals tothe primary portions 42 of the linear propulsion system 40. Each drive54 may be an inverter that transforms DC power from bus 56 to amultiphase (e.g., three phase) drive signal provided to a respectivesection of the primary portions 42. The primary portion 42 is dividedinto a plurality of modules or sections, with each section associatedwith a respective drive 54.

The controller 58 provides control signals to each of the drives 54 tocontrol generation of the drive signals. Controller 58 may use pulsewidth modulation (PWM) control signals to control generation of thedrive signals by drives 54. Controller 58 may be implemented using aprocessor-based device programmed to generate the control signals. Thecontroller 58 may also be part of an elevator control system or elevatormanagement system. Elements of the control system 46 may be implementedin a single, integrated module, and/or be distributed along the hoistway26.

Referring to FIGS. 3, 5 and 6, the primary portion 42 may include amounting assembly 60 that supports the coils 48. The mounting assembly60 may include two panels 62A, 62B that generally define the boundariesof a cavity 63 there-between with the coils 48 located in the cavity 63.Each panel 62A, 62B may include a substantially planar base 64 that maybe generally rectangular with a plurality of mounting holes 66 formedtherein. Coil cores 68 of the mounting assembly 60 support the coils 48,and may be secured to the base 64 at the mounting holes 66 via fasteners(not shown). The panel 62 and the coil cores 68 may be made from anon-conductive material, such as fiberglass, plastic, fiber reinforcedplastic, and other non-magnetic materials. However, metallic insertsand/or fluid coolant flow conduits may be present in the panels 62A, 62Band coil cores.

One or more flanges 70 of each panel 62A, 62B may be located co-planartoo, and extend from, the respective bases 64. Each flange 70 mayinclude mounting holes 72 for securing spacers 74 of the mountingassembly 60 at outer edges of the flanges 70 using fasteners (notshown). When assembled, the flanges 70 with the spacers 74 generallydefine and maintain a width of the cavity 63 to accommodate electricalwiring to the coils 48 of the primary portion 42. The flanges 70 mayalso provide desired rigidity for the primary portion 42.

Referring to FIGS. 1, 6 and 7, the linear propulsion system 40 of theelevator system 20 may further include a rail 76 and the mountingassembly 60 of the primary portion 42 may further include a bracket 78engaged between the panel 62 and the rail 76. As one non-limitingexample, two rails 78 may respectively oppose opposite sides of the car28, and may substantially extend vertically in each lane 30, 32, 34 ofthe hoistway 26. The brackets 78 of the mounting assemblies 60 of theback-to-back primary portions 48 may be secured to the rail 78. It isfurther contemplated and understood that each primary portion 48 of thetwo back-to-back primary portions 42 may generally share a commonbracket that connects to the rail 78.

The primary portion 42 may be a modular unit of the linear propulsionsystem 40. The linear propulsion system 40 may include a plurality ofmodular primary portions 42 generally aligned top to bottom along thecommon rail 76 that may extend along the entire vertical height of therespective lane 30, 32, 34. The coils 48 of each primary portion 42 maybe driven by a single, respective drive 54. In other embodiments, adrive 54 may provide drive signals to coils 48 in multiple primaryportions 42. The modular nature of the primary portions 42 facilitatesinstallation of the primary portions 42 along the length of the rail 76in the hoistway 26. Installers need only to handle the modular primaryportions 42, which are less cumbersome than more traditional designs. Itis further understood and contemplated that various configurations andnumbers of the primary portions 42 and components thereof may constitutea modular unit.

Referring to FIG. 7, the primary portion 42 may include a cooling device80 for cooling the electrical coils 48 to improve electrical efficiencyand prolong the useful life of the coils. The cooling device 80 may beof a natural or forced convection air cooling type (i.e., passive type),and may include a plurality of cooling conduits 82 (e.g., sixillustrated) and a plurality of cooling fins 84. The fins 84 may besupported by and project outward from the rail 76, and the conduits 82generally project outward from the bracket 78 and may extend through thefins for improved heat transfer via heat conduction from the conduits 82into the fins 84, and heat convection from the fins and into thesurrounding air. The fins 84 may generally be elongated andsubstantially extend longitudinally and vertically to take advantage ofnatural convection and vertical air drafts within the hoistway.

Referring to FIG. 8, the conduits 82 may be at least partially embeddedin one or both of the panels 62A, 62B of the mounting assembly 60. It isfurther contemplated and understood that the conduits 82 may also berouted between the panels 62A, 62B and in the cavity 63 that generallysurrounds the coils 48 of the primary portion 42 (also see FIG. 3).

The conduits 82 may be heat pipes, as is traditionally known in the art,that may include a center vapor cavity, a surrounding wick, and an outercasing (not shown). In operation, a working fluid in the cavity absorbsthermal energy and is vaporized. The vapor migrates along the cavity toa lower temperature end (e.g., at the fins 84). The vapor then condensesback to fluid and is absorbed by the wick releasing thermal energythrough the casing. The fluid then flows back to the higher temperatureend (e.g., at the bracket 78). It is further contemplated and understoodthat other varieties of heat pipes as is known in the art may apply.Whether the conduits are heat pipes or more passive and solid conduits,the conduits 82 may be generally made of a material having a coefficientof thermal conductivity that is about greater than 100 watts per meterkelvin. Non-limiting examples of such materials may include bronze,aluminum, copper and others. Moreover, lower conductivity metals (e.g.,steel at about 50 W/mK) may also be used.

Referring to FIG. 9, a second embodiment of a primary portion isillustrated wherein like elements have like identifying numerals exceptwith the addition of a prime symbol. A primary portion 42′ may include acooling device 80′ for cooling electrical coils of primary portion 42′to improve electrical efficiency and prolong the useful life of thecoils. The cooling device 80′ may be of an active type, and may includeat least one cooling, hollow, conduit or tube 82′ (e.g., one illustratedas a flowing liquid loop) for flowing fluid, a fluid pump 86 for drivingthe flow of fluid, and a plurality of cooling fins 84′. The fins 84′ maybe supported by and project outward from the rail 76, and a portion ofthe tube 82′ may be embedded in or formed by a bracket 78′ with anotherportion generally routed through the fins 84′ for improved heat transferinto the surrounding air. Although not illustrated, the cooling device80′ may further include temperature sensors to measure fluid temperaturethat receives signals from the fluid temperature and controls the speedand/or actuation of the pump 86. Moreover, the fins 84′ may be furthercooled via a fan or blower (not shown) located in the hoistway andconfigured to drive air flow through the fins 84′.

Referring to FIG. 10, the conduits 82′ may be at least partiallyembedded in one or both of the panels 62A′, 62B′ of the mountingassembly 60′, such that coolant flow enters the panel 62A′ via a conduitinlet 90 and exits the panel 62A′ via a conduit outlet 92 that may bedefined and carried by an outer face 94 of a flange 70′ of the panel62A′. It is further contemplated and understood that the conduits 82′may also be routed between the panels 62A′, 62B′ and in the cavity 63′that generally surrounds the coils 48′ of the primary portion 42′ (alsosee FIG. 3).

Referring to FIG. 11, a third embodiment of a cooling device isillustrated wherein like elements to the first and/or second embodimentshave like identifying numerals except with the addition of a doubleprime suffix. A cooling device 80″ may include a conduit 82″ that may bea primary coolant loop that circulates a cooling fluid generally througha mounting assembly 60″ of a linear motor primary portion 42″ and aliquid-to-liquid heat exchanger 98. A secondary coolant loop 100 mayflow fluid through the heat exchanger 98 thereby receiving heat from thecooling fluid flowing through the primary coolant loop 82″. The heatexchanger 98 may be located in or outside of the hoistway 26. Thesecondary coolant loop 100 may be constructed and arranged to transferheat into, for example, a building water heating system.

Referring to FIG. 12, a fourth embodiment of a cooling device isillustrated wherein like elements to the first and/or second embodimentshave like identifying numerals except with the addition of a tripleprime suffix. A cooling device 80′″ may include a conduit 82′″ that maybe a primary coolant loop that circulates a cooling fluid generallythrough a mounting assembly 60′″ of a linear motor primary portion 42′″and a liquid-to-air heat exchanger 98′″. A fan or blower 102 may drivecooling air through the heat exchanger 98′″ thereby removing heat (i.e.,forced air convection) from the cooling fluid flowing through theprimary coolant loop 82′″. The heat exchanger 98′″ may be located in oroutside of the hoistway 26.

The linear propulsion system 40 may include at least one primary portion42 (see FIG. 7) with the passive cooling device 80 and at least oneprimary portion 42′ with the active cooling device 80′ (see FIG. 9)along with variations thereof (e.g., cooling devices without fins, withheat exchangers, or others). The primary portion 42 may be considered asa low duty cycle portion or having a duty cycle of about less thanthirty percent, and the primary portion 42′ may be considers as a highduty cycle portion or having a duty cycle of about greater than thirtypercent. The greater the duty cycle, the greater is the heat produced bythe coils and thus the greater is the need to transfer heat away fromthe coils to improve electrical efficiency and coil life. The primaryportions 42, 42′ may be distributed along the rail 76 indicative of theexpected duty cycle at a specific location. Different duty cycles may berealized in the hoistway based on car speed and lobby level loading.Moreover, the materials used in the coils (e.g. aluminum, copper, andothers) will influence rate of coil temperature increase. It is furthercontemplated and understood that the distribution of cooling devices 80,80′ (i.e. passive and/or active) may be a function of elevator dutycycle.

While the present disclosure is described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the spirit and scope of the present disclosure. Inaddition, various modifications may be applied to adapt the teachings ofthe present disclosure to particular situations, applications, and/ormaterials, without departing from the essential scope thereof. Thepresent disclosure is thus not limited to the particular examplesdisclosed herein, but includes all embodiments falling within the scopeof the appended claims.

What is claimed is:
 1. An elevator system, comprising: an elevator carconstructed and arranged to travel in a hoistway; and a linearpropulsion system configured to impart force to the elevator car, thelinear propulsion system including; a first primary portion including amounting assembly, a plurality of coils engaged to the mountingassembly, and a first cooling device including at least one conduit loopat least partially embedded in the mounting assembly for flowing coolingfluid.
 2. The elevator system set forth in claim 1, wherein the linearpropulsion system includes a secondary portion mounted to the elevatorcar and including a plurality of magnets.
 3. The elevator system setforth in claim 1, wherein the at least one conduit loop is partiallyembedded in a panel of the mounting assembly supporting the plurality ofcoils.
 4. The elevator system set forth in claim 1, wherein the at leastone conduit loop is partially in a cavity defined at least in part by apanel of the mounting assembly that supports the coils disposed in thecavity.
 5. The elevator systems set forth in claim 1, wherein the atleast one conduit loop is made of a material having a coefficient ofthermal conductivity that is about greater than 100 watts per meterkelvin.
 6. The elevator system set forth in claim 1 further comprising:a rail disposed in and extending along the hoistway, and wherein themounting assembly is engaged to the rail and the first cooling deviceincludes a plurality of cooling fins projecting outward from the railinto the hoistway with the at least one conduit loop extending througheach one of the plurality of cooling fins.
 7. The elevator system setforth in claim 6, wherein each one of the plurality of cooling finssubstantially extend vertically.
 8. The elevator system set forth inclaim 1, wherein the first cooling device includes a pump interposed inthe at least one conduit loop for driving the cooling fluid flow.
 9. Theelevator system set forth in claim 1, wherein the cooling deviceincludes a plurality of cooling fins located outside of the hoistwaywith the at least one conduit loop extending through each one of theplurality of cooling fins.
 10. The elevator system set forth in claim 1further comprising: a rail disposed in and extending along the hoistway,and wherein the mounting assembly includes an electricallynon-conductive panel engaged to the plurality of coils and a bracketengaged between the non-conductive panel and the rail with the at leastone conduit loop partially embedded in the bracket.
 11. The elevatorsystem set forth in claim 1, wherein the cooling device includes a heatexchanger interposed with the at least one conduit loop.
 12. Theelevator system set forth in claim 11, wherein the heat exchanger islocated outside of the hoistway.
 13. The elevator system set forth inclaim 11, wherein the heat exchanger is a liquid-to-liquid heatexchanger.
 14. The elevator system set forth in claim 11, wherein theheat exchanger is a liquid-to-air heat exchanger and the cooling deviceincludes a fan for moving air through the heat exchanger.
 15. Theelevator system set forth in claim 1 further comprising: a secondprimary portion including a second cooling device including a pluralityof heat pipes.
 16. The elevator system set forth in claim 1 furthercomprising: a second primary portion including a second cooling deviceincluding a plurality of solid conduits constructed and arranged totransfer heat conductively.
 17. An elevator linear propulsion systemcomprising: a substantially vertical rail; a first primary portionincluding a plurality of first electrical coils, a first mountingassembly, and a first cooling device including a plurality of solidconduits constructed and arranged to conduct heat out of the firstmounting assembly; and a second primary portion including a plurality ofsecond electrical coils, a second mounting assembly, and a secondcooling device including at least one conduit loop for flowing coolingfluid, and wherein the at least one conduit loop extends partiallythrough the mounting assembly for cooling the mounting assembly.
 18. Theelevator linear propulsion system set forth in claim 17, wherein thefirst and second primary portions are modular portions distributed alongthe rail.
 19. The elevator linear propulsion system set forth in claim18, wherein the first primary portion includes a duty cycle of aboutless than thirty percent and the second primary portion includes a dutycycle of about greater than thirty percent.
 20. The elevator linearpropulsion system set forth in claim 17, wherein the distribution of thefirst and second cooling devices is a function of elevator car dutycycle.